Device for sealing tray-shaped or pot-shaped receptacles

ABSTRACT

An apparatus for sealing tray-shaped or pot-shaped receptacles, such as blister packs or pots for storing dairy products, includes a sealing head having a sealing contour support, a heatable sealing contour and support plate, preferably with at least one guide bolt immobilized thereon allowing for a linear displacement of the sealing head relative to the support plate. At least one spring element impinges the sealing head with a point biassing away from the support plate. A spring seat plate is disposed between the sealing head and the support plate and can be linearly displaced in the same direction as the sealing head. A rubber mount associated with the sealing head serves as a joint element and allows the sealing contour support to be tilted about the axes that are perpendicular to the guide bolts. An adjustable element is interposed between the spring seat plate and the sealing head.

The invention relates to a device for sealing tray-shaped or pot-shapedreceptacles, such as for example blister packs or pots for storing dairyproducts such as yoghurt, curd cheese or coffee cream. Said device isprovided with a sealing head comprising a sealing contour support and aheatable sealing contour and a support plate with at least one guidebolt immobilized thereon which allows for a linear displacement of thesealing head relative to the support plate. At least one spring elementimpinges the sealing head with a force pointing away from the supportplate. A spring seat plate is disposed between the sealing and thesupport plate and can be linearly displaced in the same direction as thesealing head. A rubber mount associated with the sealing head serves asa joint element and allows the sealing contour support to be tiltedabout the axis that are perpendicular to the aforementioned guide bolts.An adjusting element is interposed between the spring seat plate and thesealing head.

Blister packs are used for packaging of small components such as forexample tablets, pills or buttons, but also sensitive or comparativelyexpensive components like lenses or electronic components. The mentionedpacks consist of a more solid plastic dish with convexities where theremaining parts are kept and a foil cover which seals the convexitieshermetically. In most cases the foil cover is glued onto the dish andhas an adhesive film correspondingly which as a rule can be activatedthermally. The strength of the bonding and/or of the foil cover isadjusted in such a way that on the one hand it adheres to the dishadequately and on the other hand can also be pulled off the dish.

In the same way pasty food which has comparatively small portions can bestored in receptacles which are closed with a foil cover which is easilyremovable. For example such packaging is used for yoghurt, curd cheese,coffee cream or ready-to-serve pudding.

For applying the foil cover sealing devices will be used which as a rulehave several heatable sealing contours. The sealing contour has the taskto press the foil cover with a defined force along the outline onto thedish or the cup rim and as a result of the adjusted higher temperatureto glue the foil cover together with the receptacle. Sealing in thesense of this invention at issue means processes in which openings ofreceptacles will be closed with foils. In colloquial terms the notionbonding or welding is used.

In the actual technical state there exists a device for sealing blisterpacks, which consists essentially of a support plate and several sealingheads. There are bore holes in the support plate in which are guidebolts which are jointed firmly with a sealing head. This construction inhand allows a linear displacement of the sealing head relative to thesupport plate whereby between sealing head and support plate arrangedsprings which are enclosing bolts impinges the sealing heads with aforce pointing away from the support plate.

Each sealing head has at its face pointing away from the support plate aheatable sealing contour plate. This construction in hand due to theactual technical state the heating is a semiconductor resistor heatingand firmly integrated into the sealing contour plate. The setting of thesealing contour plate on the sealing head takes place with a cardanjoint which is carrying out here as a ball which is arranged between twoplate-formed elements of the sealing head. The ball makes tilting of thesealing contour plate with small angles possible, but also twisting thesealing contour plate about an axis which is perpendicular to thecontour.

Sealing heads and support plate forming a unit which is for implementingthe sealing attached on the foil cover of the blister pack. In thisprocess each sealing head will come after attaching of the sealingcontour into a rest position while the support plate will be shiftedrelatively to the sealing head and so far until the spring elementswhich are arranged between support plate and sealing heads produce thedesired contact pressure of the sealing contours on the foil cover.

This construction due to the actual technical state have severaldisadvantages which lead to malfunctioning and production stop of thepackaging machine.

Experience shows that an essential reason for malfunctioning lies in theconstruction of the heating. Particularly a problem is the contact ofthe resistor element which does not withstand the permanent temperature.Moreover the withstanding of the semiconductors turn out to beinsufficiently small. The disadvantage consequence is that the heatingoften breaks down and therefore has to be changed. Due to the fact thatsealing contour and heating are forming a unit, which moreover cannot beremoved when built-in with the sealing head, for changing the heatablesealing contour there has to be a complete removal of the unitconsisting of sealing heads and support plate. The disassembly requiresmuch effort which costs money and there are also production stops of thepackaging machine which cause high loss of production.

The unsatisfactory mechanical stability of the device due to the actualtechnical state has proven as a disadvantage. The setting of the sealingcontour plate on the sealing head with the help of a ball joint makesthe location of the sealing contour parallel to the foil cover possible.On the other hand it allows a twisting of the sealing contour plateabout an axis which is perpendicular to the contour. This last mentionedpossibility of motion has a special disadvantage because it hinders anexact location of the sealing contour relatively to the convexity of thelower plastic receptacle.

On the mentioned device can occur also problems with the exact set-up ofthe contact pressure of the sealing contour onto the foil cover.Herewith the spring path of the corresponding spring element must beadjusted with the help of screws which operate in axial direction of thespring. Due to the fact that these screws are not easily accessible thesetting-up needs a considerable amount of effort and cannot be doneduring operation which is of great disadvantage.

The linear guiding of the sealing heads by guiding bolts whose ends areattached to a sealing head, each one individually. The other end of theguiding bolts which functions in a borehole of the support plate has notproven as a success. In this carrying out the unity out of sealing headand guiding bolt has a long lever arm which leads from the sealingcontour to the guiding borehole in the support plate. Slight loosebetween borehole and guiding bolts causes the effect that the sealingcontour can make considerable lateral motions. These motions also hinderan exact location of the sealing contour relatively to the convexity ofthe lower plastic receptacle.

Moreover the long lever arm can cause bending out of line of the guidingbolts in the guiding boreholes. Bending out of line causing an increaseof friction between bolts and borehole whose amount is not yet defined.As a consequence the contact pressure of the sealing contour onto thecover foil fluctuates as well from contour to contour as at the samecontour from cycle to cycle. Herewith the sealing quality is diminisheddisadvantageous.

Due to this background the invention will solve the task to have devicefor sealing blister packs which avoids the mentioned disadvantages andmakes a simple and quick set-up of the contact pressure of the sealingcontour possible also an improved sealing quality and a diminishedfailure frequency and consequently decreased costs for repair andmaintenance.

Inventively this task will be solved with several, individuallyindependent realizable steps. These solutions are marked by

-   -   between each spring seat plate and sealing head there is an        adjusting element        -   with which the distance of the spring seat plate can be            adjusted relatively to the support plate            and/or    -   the joint element as rubber bearing        -   with two metal plates and a rubber layer between            -   whereas the plates are vulcanized or glued on                and/or    -   the heatable sealing contour which is assembled out of an        independent contour plate and an independent heating plate    -   and both plates        -   separable connected with each other        -   and separable attached at the sealing contour plate.

The device due to the first suggestion starts from sealing equipment dueto the actual technical state, which are provided with guiding bolts andspring elements, which enclose the bolts and are arranged between thesupport plate and the spring seat plate which adjoins the sealing head.

Differing to the actual technical state the inventive device has aspring seat plate with boreholes for moving along the guiding bolts orrelatively to them and can—in the same way as the sealing head—belinearly displaced. The position of spring seat plate relative to thesupport plate defines the length of an spring element and therefore itsinitial tension.

An essential thought in this invention at hand is the realization of thespring seat plate and its adjustable position. Therefore between thesealing head and the spring seat plate there is an adjusting elementwhich is easily accessible and with it the distance of the spring seatplate relatively to the sealing head and also to the support plate isadjustable and changeable. Displacing of the spring seat plate into thedirection of the support plate leads to an increase and displacing awayfrom the support plate to a decrease of the initial tension. The initialtension defines the after putting the sealing head onto the foil coverof the blister pack the contact pressure executed by the sealing contouron the foil cover. Consequently the mentioned adjusting element allows aset-up of the contact pressure of the sealing and the setting is quicklyand simply done. Herewith a great advantage is the free and easy accessto the adjusting element so that the set-up of the contact pressure canbe adjusted while the sealing head is built-in.

With an advantageous advance of the inventive device the mentionedadjusting element encloses a single armed lever handle which isarticulated on the sealing head (resp. the spring seat plate), whereasits first single armed lever handle pushes with its free end against thespring seat plate (resp. the sealing head) and its second armed leverhandle with its free end against an adjusting screw. Due to an essentialcharacteristic of the invention the adjusting screw is arranged such asthat it is adjustable at the face of the sealing head which is theturned off side of the support plate.

With turning of the screw the incline of the lever is changed and thenthe free end of the first armed lever handle is displaced more or lessin direction of the axis of the sealing head. The spring seat plate(resp. the sealing head) which is adjacent to the mentioned lever armreceives hereby also a translatory displacement and as a consequence thespring and the spring has a change of its initial tension. Herewith thedisplacement of the spring seat plate about the reduction ratio of bothlever arms is more decreased than the change of position of theadjusting screw. The proposed device allows advantageously a more exactadjusting of the spring initial tension.

With defining the geometrical data of the lever it is proposed that thearticulating point of the lever is arranged in an marginal area of thesealing head and that the adjusting screw is arranged in the oppositearea of the sealing head and that the free end of the one lever arm liesin the area of the axis of the sealing head. This construction allows avery precise set-up of the contact pressure of the sealing contour ontothe foil cover of the blister packs, typical measurements with devicesin practice show a change of the spring initial tension about 25 Newtonper turn.

The construction of the adjusting screw shows numerous possibilities.For the mentioned invention one solution has proven to be a success: theadjusting screw encloses a headless screw with hexagon socket head and acylindrical pin which is adjustable from the axis. Here the cylindricalpin is arranged between the mentioned lever and the mentioned headlessscrew while the headless screw stands out from the tapped hole and it isin the area of its head with a locknut adjustable. With thisconstruction the adjusting of the spring initial tension is adjustablewith effortless ease and only a few grips which are as follows: loosenthe locknut, adjust the headless screw about the necessary number ofturns and subsequently set-up the locknut again.

For the sealing quality has besides an exactly measured contact pressurealso a clean appliance of the sealing contour onto the foil cover adecisive meaning. The sealing contour plate has to make sure that thesealing contour is under all working conditions always parallel to thesurface of the foil cover adjusted. Therefore normally the sealingdevices have a joint element which allows tilting of the sealing contourplate about small angles.

This element is in the proposed device carried out due to an essentialcharacteristic of this invention as a rubber bearing with two metalplates and a rubber layer between, whereas the plates are vulcanized orglued. This construction of the joint element makes on the one hand atilting of the sealing contour in all directions possible perpendicularto the axis of the sealing contour but on the other hand no twisting ofthe contour about the mentioned axis. The proposed solution makes surethat the sealing contour is always parallel to the surface of the foilcover and in azimuth direction always an exact adjusting relative to theconvexity of the lower plastic receptacle. Both characteristics makepossible that the device due to the invention can produce high qualitysealings.

It is proposed that in the construction of the rubber bearing both metalplates on the side which shows off the rubber layer there has to be abolt which is concentric to the axis of the rubber bearing and whichengages into a borehole of the same diameter in the sealing head resp.in the sealing contour plate. Due to the proposition each bolt has aslot with a dovetail for adjusting the rubber bearing to the adjacentelements. Therefore it is provided in each sealing head and in eachsealing contour plate at least one thread-cutting screw which can bescrewed against the mentioned flank. Bolts, dovetail slot, and mentionedscrews together show a fast tension system which allows with simplemeans a secure and exactly positioned adjusting of the rubber bearing atits adjacent elements. These activities bring also the advantage thatthe rubber bearing can be changed easily for repair.

In an advantageous constructive advance of the inventive device thementioned fast tension system has an additional caution against twistingof the rubber bearing: In this carrying out each metal plate outside theaxis of the rubber bearing has a borehole in which engages a cylindricalcentering pin which is adjusted at the sealing head and the sealingcontour plate. These last mentioned constructive actions lead to a spaceand twist-free adjusting of the rubber bearing which have a high sealingquality as a result.

The proposed constructive activities of this mentioned invention forimprovement of the sealing quality and for decrease of the failurefrequency enclose also the heating of the sealing contour. As alreadyshown has the inventive device a heatable sealing contour assembled outof an independent contour plate and an independent heating plate. Due toan essential characteristic of the invention both plates are separablejointed with each other and separable adjusted at the sealing contourplate. This carrying out has as a result an essential improvement formaintenance and repair, because of a defect of the heating or thethermostat only the heating plate has to be replaced. And there neednot—as with sealing devices due to the actual technical state, thecomplete unit out of sealing head and support plate has to be build out,but only the defect heating plate. Because the contour plate and theheating plate are separably with each other joint, the disassembly andassembly of both elements need only a small amount of time an can beespecially without disassembly of other elements of the device carriedout.

An especially preferred constructive advance of the inventive deviceprovides moreover with a drastic decrease of the number of repairs. Inthis carrying out the heating plate is a flat heating preferably formedas ceramics flat heating or heating plate with heating cartridge. Copperand/or aluminium is especially preferred as material for the heatingplate and/or also for the flat heating due to their thermal conductance.Both carrying outs have a long endurance therefore a change of theseelements is only in comparable large periods necessary. Long periods ofproduction stops of the packaging machine and subsequently high loss ofproduction caused by defect heating plates does not take place with thehere mentioned inventive device.

There are further constructive actions with the same target namelyincreasing the endurance of the device as long as possible. These carryout that the contour plate consists of hardened material or out of amaterial which is resistant against aggressive substances preferablyrustproof steal. The life of the contour, the resistance againstmechanical stress and resistance against aggressive substances which candischarge within the sealing process out of the convexity of the plasticreceptacle have increased to a higher value.

The usual temperatures during the sealing of blister packs have 200centigrade Celsius. This temperature is during action permanently validon the device at the contour plate. One characteristic of this inventionis the providing of at least one thermal insulating layer betweenheating plate and ball element for hindering heat drop to the arrangedelements of the lower section of the sealing contour plate which on theone hand has as a result undesired loss of energy and on the other handthe thermal overload of the assembling elements of the sealing head.

This mentioned invention has also for the linear guiding system adifferent solution as the actual technical state provides. This ismarked by the characteristic that the mentioned guiding bolts are firmlyand rigidly adjusted on a base plate which is firmly adjusted on asupport plate and the linear displacement of the sealing head takesplace relative to the base plate through a displacement of the sealinghead relative to the guiding bolt. The sealing head has correspondingboreholes provided for ball bearings which themselves are functioning onthe guiding bolts. The change of the support point of the guiding bolthas—compared to the actual technical state—as a result a shorter leverarm for reduction of motional resistance caused by moments throughbending out of line of the bolts. The ball bearings allow smooth-runningof the bolts, which allow also the realization of a short work cycle.

The solution compared to the actual technical state in which the guidingbolts are adjusted with their first end at the sealing head while theirother end functions in a borehole of the support plate the proposedconstructive action results in an essentially improved guidance of thesealing head. Bending out of line of the guiding bolts in the guidingboreholes cannot appear with the mentioned device from the first. Thefriction caused by the mentioned bending out of line between bolts andboreholes with an undefined effect on the contact pressure of thesealing contour on the foil cover of the blister packs is from the firstout of question.

Especially lateral motions of the sealing head are omitted because ofthe rigid adjusting of the guiding bolts on the base plate which withthe usual conventional carrying out of the linear guiding are available.The cause is the clearance between borehole in the support plate and theguiding bolt and which hinder an exact location of the sealing contourrelative to the convexity of the lower plastic receptacle.

Moreover the carrying out of the sealing head with ball bearingseliminates as far as possible the friction between guiding bold andsealing head at a linear displacement of the sealing head and avoidsherewith also undefined effects on the contact pressure of the sealingcontour.

Special attention at the mentioned invention for sealing blister packsis located on a maintenance-friendly assembly. As already mentionedessential elements such as contour plate, heating plate or rubberbearing are free and easily accessible carried out, separable togetherjoint and without disassembly of other elements changeable. Moreoverthere is as a characteristic of this invention a module assemblyprovided with which

-   -   a sealing head with        -   a contour plate        -   a heating plate        -   a or several insulating plates,        -   a joint element and    -   a spring seat plate,    -   two guiding bolts,    -   two spring elements        on the base plate assembled and therefore form an independent        unit, the sealing position. Moreover there are several of the        mentioned sealing positions for example four, on the same base        plate arranged and form in this kind a larger unit, the sealing        row. Several sealing rows, for example five, are also separable        on the support plate assembled and finally form together the        base unit of the device, the sealing station. The electrical        cables will be supported to the base plate in this carrying out        by each a multipolar connector, each engaged with a        complementary formed connector. Advantageous is a definite        relation of the base plate to the support plate for securing        that no wrong assembly or assembly with mistakenly exchanged        sides assembly takes place. Therefore the change can also take        place with temporary workers.

The proposed assembly secures a simple changeability of the sealing rowsand the sealing station. Together with the above mentioned actions,which secure the simple change of the essential single elements there isalso an easiness to maintain and repair and an easy mode of application.Moreover the proposed assembly allows simple measuring and adjusting ofthe necessary temperatures and the force which is exercised from thesealing head onto the pack which has to be sealed. Herewith a measuringinstrument with sensors for each sealing contour plate is arranged onthe sealing station, the actual values of the temperature and thecontact pressure investigated and subsequently the heating and the leveradjusting individually on each sealing head onto each set valuewell-regulated.

More details, characteristics and advantages of this invention you canlearn from the following part of the description. In this part anexample for carrying out of the inventive device for sealing blisterpacks will be commented with a drawing.

FIG. 1: shows in a schematic representation a diameter of a sealingposition

FIG. 1 is the fundamental assembly of a unit, which is above mentioneddescribed as sealing position. It represents a complete unit forproducing a sealing contour and encloses the following elements: contourplate 1, heating plate 2, insulating plate 3, joint element 4, sealinghead 5, lever element 6, spring seat plate 7, guiding bolt 8, springelement 9, base plate 10, support plate 11.

Due to a characteristic of the invention the guiding bolts 8 are rigidadjusted in the base plate 10 whereas the base plate itself is separableassembled with the support plate 11. In the here mentioned carrying outthe spring elements are formed as coil springs which enclose bolt 8 andare arranged in the space between base plate 10 and spring seat plate 7.As shown in the figure the spring seat plate 7 has 12 boreholes whichmake possible a relative displacement of the spring seat plate 7 to theguiding bolts 8. A displacement of the spring seat plate 7 into thedirection of the support plate 11 leads to a contraction of the springs9 und consequently to a increase of the spring initial tension.

The displacement of the spring seat plate 7 can be activated with asingle armed lever handle 6 which is guided in point 13 on the sealinghead 5. The lever is formed in such a way, that its first lever arm withits free end 14 pushes against the spring seat plate 7 and its secondlever arm with its free end 15 pushes against an adjusting screw, whoseposition in the mentioned drawing is indicated with a line-dotted line16. The position is chosen such as that the adjusting screw can bereached from the face side 17 of the sealing head 5.

Marked with 18 are the ball bearings in which boreholes withcorresponding diameters of the sealing head 5 are arranged. They allowafter the attachment of the sealing head onto the foil cover 19 of theblister pack 20 the linear displacement of the sealing head 5 onto theguiding bolt 8 into the direction of the support plate 11. The forceproduced by the initial tension of the spring elements 9 are transferredherewith onto the contour plate 1 and provides an even contact pressureonto foil cover 19.

For the quality of the sealing is decisive not only the exactly measuredcontact pressure but also a clean appliance of the contour plate 1 ontothe foil cover 19. Therefore the here mentioned inventive device isequipped with a joint element 4 which consists out of two metal plates20, 20′ and a rubber layer 21 which is enclosed between the plates. Thiselement makes a tilting of the contour plate 1 in all perpendiculardirections about the axis 22 possible but hinders a twisting of thementioned axis.

The rubber bearing 4 secures that the contour plate 1 is always paralleladjusted to the surface of the foil cover 19 and no twisting about theaxis 22 takes place.

At the rubber bearing 4 the sealing contour support 23 will be appliedwith all the necessary elements for sealing. This consists of contourplate 1 and heating plate 2. Both components are formed as independentelements and joint with each other but separable. For hindering atemperature drop from these elements into the direction of the rubberbearing 4 there is assigned between heating plate 2 and the jointelement 4 a thermal insulating plate 3.

As a result the here mentioned inventive device ensures a simple andquick adjustment of the contact pressure, a high sealing quality, anoptimal accessibility to all assembly elements and negligible failurefrequency.

1-16. (canceled)
 17. An apparatus for sealing tray-shaped or pot-shapedreceptacles, comprising: a sealing head having a sealing contour plateand a heatable sealing contour; a support plate; means for linearlydisplacing said sealing head relative to said support plate; a springimpinging said sealing head and said support plate, said spring exertinga force biassing away from said support plate; a spring seat platebetween said sealing head and said support plate, said spring seat platebeing arranged in a direction that is the same as a direction of lineardisplacement of said sealing head; a joint element for tilting saidsealing contour plate of said sealing head perpendicularly to an axis ofsaid means for linearly displacing said sealing head relative to saidsupport plate; and, means for adjusting distance between said springseat plate and said support plate, said means for adjusting distancebeing between said spring seat plate and said sealing head.
 18. Theapparatus for sealing tray-shaped or pot-shaped receptacles according toclaim 17, wherein said means for linearly displacing said sealing headrelative to said support plate includes an adjustable guiding bolt. 19.The apparatus for sealing tray-shaped or pot-shaped receptaclesaccording to claim 17, wherein said means for adjusting distanceincludes a lever handle having a first lever arm able to push with itsfree end against said spring seat plate or said sealing head and asecond lever arm able to push with its free end against an adjustingscrew.
 20. The apparatus for sealing tray-shaped or pot-shapedreceptacles according to claim 19, wherein said adjusting screw isaccessible from a face side of said sealing head, said face side being aside of said sealing head point away from said support plate.
 21. Theapparatus for sealing tray-shaped or pot-shaped receptacles according toclaim 19, wherein said adjusting screw encloses a cylindrical pinrelocatable to a direction of its axis and a headless screw with ahexigonal socket head, said cylindrical pin being between said secondlever arm and said headless screw.
 22. An apparatus for sealingtray-shaped or pot-shaped receptacles, comprising: a sealing head havinga sealing contour plate and a heatable sealing contour; a support plate;means for linearly displacing said sealing head relative to said supportplate; a spring impinging said sealing head and said support plate, saidspring exerting a force biassing away from said support plate; a springseat plate between said sealing head and said support plate, said springseat plate being arranged in a direction that is the same as a directionof linear displacement of said sealing head; and, a joint element fortilting said sealing contour plate of said sealing head perpendicularlyto an axis of said means for linearly displacing said sealing headrelative to said support plate, said joint element including a rubberbearing and two metal plates and a rubber layer between said two metalplates.
 23. The apparatus for sealing tray-shaped or pot-shapedreceptacles according to claim 22, wherein each of said two metal plateshas a concentrical bolt on a side of metal plate facing away from aidrubber layer, each of said two metal plates having a slot with adovetail flank and with at least one screw screwable against saiddovetail flank and provided in said sealing head.
 24. The apparatus forsealing tray-shaped or pot-shaped receptacles according to claim 22,wherein each of said two metal plates has a bore outside of an axiscreated by said rubber bearing, said bore of each of said two metalplates being intersected by an adjustable cylindrical centering pin. 25.An apparatus for sealing tray-shaped or pot-shaped receptacles,comprising: a sealing head having a sealing contour plate and a heatablesealing contour, said heatable sealing contour comprising, and beingassembled from, an independent contour plate and an independent heatingplate separably joined together and separably adjustable at said sealingcontour plate; a support plate; means for linearly displacing saidsealing head relative to said support plate; a spring impinging saidsealing head and said support plate, said spring exerting a forcebiassing away from said support plate; a spring seat plate between saidsealing head and said support plate, said spring seat plate beingarranged in a direction that is the same as a direction of lineardisplacement of said sealing head; and, a joint element for tilting saidsealing contour plate of said sealing head perpendicularly to an axis ofsaid means for linearly displacing said sealing head relative to saidsupport plate.
 26. The apparatus for sealing tray-shaped or pot-shapedreceptacles according to claim 25, wherein said independent heatingplate is a flat heating plate.
 27. The apparatus for sealing tray-shapedor pot-shaped receptacles according to claim 25, wherein saidindependent heating plate includes a heating cartridge.
 28. Theapparatus for sealing tray-shaped or pot-shaped receptacles according toclaim 25, further comprising a thermal insulating layer between saidindependent heating plate and said joint element.
 29. The apparatus forsealing tray-shaped or pot-shaped receptacles according to claim 25,wherein said sealing contour plate is made of a hardened material. 30.The apparatus for sealing tray-shaped or pot-shaped receptaclesaccording to claim 25, wherein said sealing contour plate is made ofrefined steel.
 31. The apparatus for sealing tray-shaped or pot-shapedreceptacles according to claim 25, wherein said means for linearlydisplacing said sealing head relative to said support plate includes anadjustable guiding bolt.
 32. The apparatus for sealing tray-shaped orpot-shaped receptacles according to claim 31, further comprising a baseplate with said adjustable guiding bolt being adjustable at said baseplate.
 33. The apparatus for sealing tray-shaped or pot-shapedreceptacles according to claim 32, wherein said linear placement of saidsealing head is activated relative to said base plate with adisplacement of said sealing head to said adjustable guiding bolt. 34.The apparatus for sealing tray-shaped or pot-shaped receptaclesaccording to claim 31, wherein said sealing head includes ball bearingswhich are activated on said adjustable guiding bolt.